Cooling tower



COOLING TOWER Filed Deb. 2a, 1936 4 Sheets-Shea 1 COEY COOLING TOWER Filed Dec. 28, 1936 4 Sheets-Sheet 2 s. c. coEY v COOLING TOWER Filed Dec. 28, 1936 4 Sheets-Sheet 3 May 2, 139. Q CQEY 2,157,070

COOLING TOWER Fild Dec. 28, 1936 4 Sheets-Sheet'4 Patented May 2, 1939 UNITED STATES PATENT; OFFICE 1 Stewart 0. Coey, Glen Ridge, n. J.

Application December 28, 1936, Serial No. 117,996

17 Claims.

This invention relates to liquid cooling towers and more particularly to such towers cooled by gorcfed air currents as distinguished from natural It is a general object of the present invention to provide a novel and improved type of liquid cooling tower.

More particularly it is an object of the invention to provide a multi-stage liquid cooling tower using forced air circulation.

An important feature of the present invention,

in addition to the structural features which permit of low cost and compact size, resides in the use of multi-stage cooling in which the air flows 1| countercurrent to the liquid and all of itpasses .in successive stages through the liquid, whereby the total amount of air required to be circulated to produce a given temperature change inthe liquid is substantially 50% less than that required in single stage cooling, obviously effecting material savings in size and operating expense of the tower;

Another important feature of the tower of the present invention consists in the provision of means forusing an air circulating device of the so-called squirrel cage type and through which all of the air used by the tower passes radially and which is preferably arranged lnterstage, producing at least one stage of suction cooling and one or more stages of pressure cooling. This absolutely ensures against the formation of ice on the blades of the rotor in the coldest weather.

A further feature of the invention resides in the provision of a multistage forced'draft cooling tower in which all of the air passes at substantially right angles to the falling liquid in each stage. I

Still another feature of the invention resides in the provision of a novel spray eliminator which acts to remove entrained moisture from the upwardly moving air current by changing the velocity and direction of the current and catching the moisture droplets which tend to continue in a straight line and returning them directly to the 4 receptacle for hot liquid whereby they are again delivered into the tower for cooling.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying 5 drawings and following specification, wherein is disclosed exemplary embodiments of the invention, with the understanding, however, that various changes may be made therein, such for instance as in the number and disposition of the 5 stages, in the arrangement and structural features of the liquid battles, and any other points of construction and arrangement ofparts such as fall within the scope of the appended claims without departing from the spirit of the invention.

In said drawings,

, Figure 1 is a vertical central section through a cooling tower constructed according to the present invention;

Figure 2 is a horizontal section thereof taken on line 2-4 of Figure 1;

Figure 3 is" a fragmentary plan view of the tower with part of the spray eliminator broken away to show the interior construction;

Figure 4 is a fragmentary section on line 4-4 of Figure 2 showing the manner of supporting it the liquid distributing baiiles;

Figure 5 is a fragmentary chordal section on line 5-5 of Figure 3, showing the arrangement of the spray eliminator vanes;

Figure 6 is a schematic, cross sectional eleva- 20 tion of another embodiment of the invention;

' Figure 7 is a horizontal cross sectional view taken substantially on line I! of Figure 6;

Figure 8 is a horizontal cross sectional view taken substantially on line 8-8- of Figure 6.

With the increase in the use of refrigeration and room cooling machinery and the increase in power of engines, there have been added demands for increased capacity cooling towers for handling the cooling liquid, condenser water and the 30 like. The added demands placed on the municipal water supply systems by such apparatus, where cooling and re-use of the water is not resorted to, has brought about legislation in many cities limiting or entirely prohibiting the-use of 35 water for cooling purposes where it is not cooled and re-used.

. Heretofore cooling towers of various types have been used with more or less success, but previous types have been open to various objections. The 40 natural draft towers are seriously limited in their cooling capacity on still days, so that they must be built of adequate size to produce all of the required cooiing on just such days, which makes them extremely cumbersome and the weight becomes a critical factor since they are usually supported. on the roofs of buildings. In addition, they are unsightly, costly and require considerable upkeep. Of the various types of forced draft cooling towers objections have been. voiced as to the expense of operation, for instance, for the cost of power to operate the blowers. These towers are often costly to build and are bulky and.heavy. Most previous types of cooling towers have been subject to the very serious objection of spray dis- 'semination, sometimes resulting in law suits ainst their users by owners of adjacent property. Then too, the amount of water lost by spraying is a very considerable item and adds that much to the cost of operation of the apparatus. Towers which are large, particularly in height,

v sometimes reach above the level allowed for per minute, and the temperatures in the various buildings where certain restrictions are placed thereon and increased height also means increased cost of operation because of the addi-' tional pumping head.

The tower of the Present invention can be made of less than half the volume of heretofore 7 known cooling towers of the forced draft type and probably less than to of. the volume of a natural draft cooling tower of the-same capacity. pumping head; is compact and sightly, requires little power for operation, permits of a greater cooling range than heretofore available and is withall less costly than prior forms of towers.

The improved results'attained with the tower of the present invention'are essentially deriiled from the multistage operation wherein the same air passes countercurrent a number of times through the water. This makes use of the air to-its fullest extent. To illustrate the application of this principle it may be mentioned that in computing the results to be attained by a single stage cooling tower where it was desired to cool 800 gallons per minute of water from 100 F. to 80 F. with an atmosphere wet bulb temperature of 75 F. it was found that on the single pass principle it was necessary to .a tower delivering 255,000 cubic feet of air per minute to accomplish the result. With a threestage cascade tower the same result could be accomplished delivering 120,000 cubic feet of air 16 is low in height to reduce themer ers plate i8, and as shown in Figure 2, the twocolumns i5, it of a pair lie in a radial plane passing through an apex ll of the octagonal plate l3 and on each such plane is a corresponding pair. These columns maybe rectangular metal bars of adequate strength and each pair is se-.

cured together into a ladder-like formation by means of horizontal angle bars to, is suitably secured thereto as by welding or riveting. As shown in Figure 4, these angle bars are placed back to back against the columns and extend the full distance between the columns oi a pair.

Their horizontal flanges are at the bottom, and

they are spaced apart one. above the other as will-be further described.

At about one-third of the height of the columns they may pass through and support intermediate water distributing trough 20. If the columns pass through bottom plate 25 of this trough suitable means is provided to prevent leakage, or the columns can be separated and the tray inserted between their ends although structurally the first method is preferred. This trough has peripheral flange 22 similar in contour and size to that on the bottom tray.- The trough is substantially annular and is provided with large circular aperture 23 surrounded by narrow horizontal flange 2S and the wider inclined flange 25. v

At the top of the columns is supported a sec-, ond trough 28 having a substantially annular bottom plate 29 secured to the tdps of the columns, a peripheral flange 30 extending both above and .below the plate 29 and inner flange 3! extending to.the same heightas the upper part of the outer flange and forming asubstantially annular trough into whichis delivered by pipe 32 the hot water to becooleoi- Overflow of the entering water due to its velocity is preventstages would be as follows: ed by the short cover sheet 32'. The trough is Air Temp. wet bulb 'Water temp. B: t. u. removed Water Pass flow, P83

in out in out cubic Total footair I Degrees Deg-rm Decrees Degrees 1 a; 80 mo so sou 0.555 c an 2 is as c 84 sec 0.3% 40,000 a 75 7s 84 so soc .212 issue Netover all... 75 so 100 an em in, an

Resting on these beams and secured thereto in any desired manner is the cooled water tray or receptacle l2 preferably of circular or p onal shape. As shown, it may be octagonal for ease in construction and comprises bottom plate l3 and suitable edge plates secured thereto in a -water-tight manner and forming the shallow tray to receive the water after it has been cooled in the tower. The tray may be equipped with discharge pipe I for taking of! the water for re-use.

A plurality of pairs of vertical columns IE, IS are secured with their lower 'ends resting on divided into inner and outer sections so and st uniform overflow of water around the periphery of the dam into inner section 8 3 of the upper tray, which just to the inside of the dam has its bottom perforated by acircular series of holes 36 through which the water delivered over the dam flows with substantially uniform volume so that heated water is discharged from the upper trough in a plurality of substantially uniform streams in what may be termed a circular curtain.

Between the middle and upper troughs are arranged a plurality of bellies-each comprising spaced wooden strips 38 chordally disposed with their ends resting on the lower flanges 39 of u the angles l8, l9 connecting the supporting columns together. Each strip 38 extends from the angle on one column to that on the adjacent one and the strips are spaced apart laterally to provide spaces for waterto drip through between the slats. The spaces between slatsin alternate baflles are in staggered relation, as clearly seen in Figure 1, so that in no case can water drip, without being completely stopped in its fall, more than the vertical distance between adjacent layers of slats. This is an extremely important provision, since it materially reduces the rate of dropping of the water and gives it a much longer time of contact with the cooling air.

It will be remembered that the distance'travelled by a freely falling body, for instance, a drop of water, is a function of the square of the time, i. e.,

where h is measuredin feet, 9 is the gravity constant 32.2 and t is time in seconds. Considering a case where there are nine sets of slats spaced eight inches apart vertically, it would take water 1.836 seconds to travel the six feet from the upper slat to the bottom slat, since each' drop of eight inches would start from zerovelocity, whereas in the same length of. time if the flow of the water were not stopped periodically it would fall 54.2 feet.

The inner and outer slats of each section have their inner and outer edges, respectively, elevated, as shown, so that these slats are inclined toward the horizontal slats, ensuring that all of the drip shall be-in-ward and onto the succeeding lower baffle and hence shall not be discharged out beyond the edges of the lower baflles and drop freely. Any adequate means for supporting these inclined slats can be resorted to, such as the use of positioning blocks of triangular shape beneath them. For securing the slats to the lower flanges of the angles anysuit- I slats above the trough 20, it is collected in this trough largely on the outer section 42 thereof, which is separated from the inner section 43 by a dam 44 identical in construction to that described in connection withthe upper trough. The reasons for the collection of most of the water in the outer section will be clear from further description. The water flowing over the dam into the inner section 43 drops through a series of holes 45, as in connection with the upper trough and then falls down over a similarly constructed series of slatted baffies 46 until it is finally. discharged into the bottom or cooled water vtray l2. The space enclosed by the tiers of bafiles may ,bejlike'ned to a chimney. .The. bafiles in the. lowersection or first'cool ing stage, existing between the bottom tray andintermediate trough are fully exposed to the outside atmosphere on their outer peripheries since there is no enclosure around them, as clearly seen in Figure 1. However, the second twocooling stages accommodated between the intermediate and top troughs are completely shielded from the atmosphere by a spaced, en-

a closing shellor casing, 'which'is seen in Figure 2 to comprise plates 5| of suitable sheet 'metal each with"o'ne'-vertical' edgebentinto a flange 53 to overlap the adjacent plate and form with the other plates a hollow octagonal prism. The plates are adequately secured to the edge plates of the top and intermediate troughs which they overlap, as seen at 54 and 55 in Figure 1.

For the purpose of circulating air upwardly through the chimney portion of the tower there is provided a squirrel cage type of fan rotor 56 mounted on vertical shaft 51 having bearing in sleeve 58 extending between the bottom plate 13 of the bottom tray or receptacle and spider 59 secured to the inclined flange 25 of the intermediate trough. A suitable step bearing 60 supports the lower end of this shaft and is itself carried by suitable structural parts 6|. A large pulley 62 on this shaft may be driven by any suitable flexible drive, such as a link'belt or V-type belt 63, from the pulley 64 on the vertically mounted motor 65.

The rotor comprises a solid, fiat, circular metal plate 66 mounted on the flange 61 of the hub 68 on the shaft 51. This plate is of such a diameter that it just freely rotates withinthe space between the edges of the slats in the water baflles and has depending therefrom a series of vanes 69 of appropriate configuration and inclination to the radial to form what may be considered as a squirrel cage rotor, such as used in various air delivering blowers. The design of this rotor is not a part of the present invention, since itmay be constructed in accordance with several well-known types. The outer edges of the blades just clear the baiiles and the lower clipped tips ID of the blades run very close to the flange 24 on the intermediate water trough.

It will be appreciated that the air is discharged from this rotor or fan in substantially radial flow lines but that the suction is more nearly axial and of course from below only on account of the enclosing plate 66 at the top.

In operation, the rotation of the fan in atvtempting to draw air axially into its blades produoes a suction which draws the air horizontally inwardly between the water bafiles in the first or lower stage of the tower. This air has free access to the outer portions of said bafiles and in passing horizontally between the slats thereof moves substantially at right angles to the water dripping down between the slats so that allof. the air is brought into contact with all of the water which is thus cooled. The entering air is at its coolest as is the water by the time it has reached the last stage so that adequate cooling takes place.

The air is'then drawn into the fan, passes radially outwardly through the blades and is discharged through what I may be considered the second or intermediate stage of cooling, reaching from the intermediate trough to the bafile 15 at the level of the top plate 66 of the rotor. All of the air which has entered into the first or bottom stage is thus discharged through the second. or intermediate stage again horizontally and at right angles to the'dripping water, so all of the air again comes in contact with all of the water, each at its intermediate temperature. The water may be at least partially blown to the outer parts of the air passes again through all of the water in that section above the baille 15 and extending to the upper trough. Here the water is at its maximum temperature, but since the air is cooler than the water. there is adequate heat transfer as well as the usual cooling by evaporation. In the transfer of the air from the second to the final stage theremay be some air escape vertically upwardly between the stats of the water baflies, but eventually it all moves inwardly and across the dripping water. The example quoted previ-- ously will illustrate the rate at which heat is removed from the water in the three successive stages. The first stage removes about half of the total heat, the second stage a little less than one-third, and the final stage the remainder.

The arrows in the drawings showing the air flow indicate the stream line movement thereof which produces maximum efllciency with minimum power for driving the blower. The three passes of the air are obtained with minimum change of direction of flow and with an extremely simple construction.

The air discharged from the tower must pass up through the central aperture defined by the inner peripheral flange 3| of the upper trough,

' and since there is a possibility of some moisture entrainment, a novel form of spray eliminator is provided comprising what may be briefly defined as a stationary fan of the multi-bladed propeller type. .Such a fan is removably supported from the rim of a horizontal wheel 80 carried by a plurality of struts BI secured around its periphery and extending downwardly and being attached to the flange 3| of the top trough. The wheel is of substantially the same diameter as this flange and is equipped with spokes 82 mounting a hub 83 which removably supports a bar 84 to the upper end of which is attached a flat, circular, metal plate 85.

The plate 85 and the wheel 80 form two supports ior each of the blades or vanes 06 of the spray eliminator, which in general appears as a frustrum of a cone as seen in Figure 1. Each blade has its upper or inner end secured beneath plate 85 and its intermediate portionresting on the ring 80. In general each blade inclines downwardly so that water from its under surface drips downward by gravity and falls from the end of the vane which is mounted directly over the outer section of the upper water trough so that the water is returned for use. Each vane 86 is inclined in a transverse manner at about 40 to the horizontal as seen in Figure 5 and each blade overlaps materially the succeeding blade so that air cannot pass directly vertically out of the tower but is broken up into minor streams, all given an inclined movement by virtue of the stationary fan-like eliminator blades which have the reverse action on a moving column of air as a rotary fanwould have on a stationary body of posited there by the sudden change in direction of the air, and being blown toward its outer edge is caught by this trough-like projection and is d rected downwardly and longitudinally of the blade so that ,it is returned to the upper hot water trough. The amount of water escaping in the form of entrained droplets is extremely small. Practically the only water wasted by the tower is that evaporated for the purpose of cooling, and

this cannot be considered as a waste since the evaporation is essential to the cooling of the water, there being but little actual transfer of heat from the water to the air. The loss by evaporation is about .1% per degree temperature change of the water and the total so-called spray loss can be considered as well within 0.5% per hour of the total quantity of water handled.

Another embodiment of the .invention is illustrated schematically in Figs. 6, 7 and 8. In this form of theinvention the tower consists of superposed groups or banks of evaporative coolers, each cooler comprising a plurality of superposed finned pipes extending between headers. Liquid to be cooled is circulated through the pipes and other liquid is distributed over the top-pipes of the coolers whereby it falls from pipe to pipe and on the fins, cooling being effected by passing air through the coolers evaporating some of the liquid. The pipes correspond to the bailles of the first embodiment of the invention, the fall of the liquid forming the curtain being interrupted periodically by the same.

Referring to Figs. 6, '7 and 8, the evaporative coolers or heat exchangers are shown as comprising vertical end headers I connected by vertically spaced horizontal pipes IOI carrying vertical fins I02 in the form of thin sheets having holes therethrough for the pipes.. At the top of each cooler there is a channel or liquid feed trough I03 suitably secured to the headers and formed with a lengthwise slot I04 in its bottom wall for distributing liquid over the pipes and flns.

These coolers are arranged to-form a hollow tower or chimney, polygonal in cross section. As shown, four coolers are disposed at each pass or level forming a substantially closed four-sided figure, and as seen from Fig. 6, the tower has four banks or horizontal groups of coolers arranged vertically, one above the other.

A casing I05 surrounds the tower of coolers and is closed by the top I 06 having a manhole and cover I01. The lower end of the apparatus has a re-entrant wall I08, forming with the outside' wall of the casing, liquid receptacles I09.

The interior of the tower at an elevation corresponding to the tops of the walls I08 is closed by a partition H0.

The air for evaporating some of the water or cated by reference letter B. Suitable partitions H4, and H5 are provided to keep the inlet and outlet currents of air separated. The interior of the tower just above the fan is suitably closed by partition IIG which carries a bearing II I for the fan. The fan shaft H8 projects downwardly through partition II 0 and at its lower end is supported by a bearing H9. The shaft is suitably driven from a motor I20 by the belt and pulley drive I2l-.

The partitions II 6 and I22 are provided with vertical walls I23 and I24, respectively, thus forming a receptacle or trough for collecting water as will be presently described.

The air leaving the coolers B, by means of the bailles I25, I26 and the outside wallof the cas- I31 to the supply pipe I30.

ing, is directed inwardly through the next bank of coolers indicated by the letter C. Finally the air moving into the interior of the tower through the bank C of coolers is discharged outwardly through the bank D, suitable baiiles I21 and I28 being provided to aid this. From the bank D of coolers the air passes outwardly through the spray eliminators I29 into the atmosphere.

The liquid to be cooled is supplied through pipe I30. A portion of this passes through the coils or pipes of the coolers and another portion is distributed over-the top pipes and drops from pipe to pipe to efiect the evaporative cooling.

As shown, above the top bank D of coolers, is a liquid header pipe I3I provided with nozzles I32 delivering liquid into the top channels or troughs I03. The liquid then passes through the slot I04 in the header and falls onto the pipes and fins of the coolers, thus forming a liquid curtain that is interrupted periodically in its fall. From their lower portions the coolers D discharge into the upper channels of the next bank C of coolers, suitable deflecting plates II3 being provided for this purpose The evaporative water passes downwardly over the coolers C and is collected in the receptacles I34.

As stated, the header l3l is supplied from pipe I30, a suitable valve I35 being provided to con-' trol the flow. For the liquid supplied to the interior of the pipes of the coolers, a header I36 is employed which may be connected through pipe Valve I38 is provided to regulate the fiow. As clearly shown in Fig. 7, the header I36 is connected to the upper part of the coil of each cooler by a connection I39. Each' of the coils in the coolers of bank 13 is connected to the coil in the next lower bank C by a pipe connection I40. Each of the coils of the coolers C has a discharge pipe I4I- for delivering the cooled liquid into the receptacles I34. From the foregoing, it is seen that a portion of the liquid is cooled by evaporation and another portion is cooled by heat transfer from the coils to the cooled evaporative liquid and the air passing over the coolers.

' For supplying liquid to the two lower banks Band A, a header I42 with nozzles I43 is provided and for the coils there is a header I44 connected to the coils in the same manner as described for bank D. Liquid to be cooled is' supplied through pipe I45. which is connected to header I42 by pipe I46 having a valve I41 therein and to header I44 by a pipe I48 having a valve I49 therein.

The evaporative water supplied from header I42 passes downwardly over the banks B and 'A of the coolers, being interrupted periodically in its fall, and is collected in receptacles I09 pro.

vided with suitable partitions I50 to prevent bypassing air around the bottoms of coolers A. The

other portion of water supplied to the coils of coolers B is delivered by connections l5l to the corresponding cooler in the next lower bank and the coolefA shown at the left of-Fig. 6, the movement air is transversely inwardly through I this cooler and the cooler is supported so that, as a whole, it is inclined toward the right, or direction of flow.

Any suitable means may be employed for supporting the coolers. Thus as shown, the header I00 may be fastenedto corner walls I53 by angles I54. These are shown in Fig. 8, but are omitted from Fig. 6 to avoid confusion. It will be noted that there are two supplies of liquid to be cooled, one through pipe I30 and the other through pipe I45. These supplies may be at the same or different temperatures' For instance, in one use of this tower, water at 85 F. is supplied through 1 pipe I30, The discharge from the receptacle I34 through pipe I55 is at a temperature of 81 F. For the lower banks B and A of coolers the water was supplied at 75 F. and discharged through pipe I56 from receptacle I09 at a temperature of 71 F.

In this particular instance, the air supplied through the opening II I in the casing had a wet bulb temperature of 66 F. When it left the bank B of coolers its wet bulb temperature was 72 F. and when discharged from bank D its wet bulb temperature was 79 F. i

Although an embodiment of the invention has been shown as consisting of four banks of superposed coolers, it is clear that a greater or less number might be employed. Furthermore, instead of cooling liquid supplied at two temperatures, the tower might be adaptedtocool liquid from one temperature to a lower one, two or more banks of coolers being employed.

This application is a continuation-in-part of my application, Serial No. 683,860, filed August 5, 1933. Having thus described theinvention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a cooling device for iliquids in combination, a tower including'baflle to fall from top to bottom hereof in adjacent concentric curtains interrupted periodically in velocity only to retard the fall and a single air cans to cause liquid.

same air to pass through all of the liquid curtains a. plurality of times and in alternate directions.

2. In a liquid cooling tower, in combination, a superimposed series of annular baflles, means above said series to .distribute hot liquiduniformly over the topmost baiile, means below the lowest baiile to catch the cooled liquid, a squirrel cage type fan rotor within said baflle series between the top and bottom thereof, the baiiles below the rotor being exposed to atmosphere on their outerperipheries, an enclosing casing surrounding the bailles at and above the rotor, and a spray eliminator above the center of the baffle stack.

3. In a liquid superimposed series of annular baflies, means above said series to distribute hot liquid uniformly over the topmost baille,'means below the lowest baflie to catch the partly cooled liquid and redistribute it, a second similar series of bailies liquid distributor, means closing the bottom of the tower, means closing the top of the rotor and the opening in the center of the trays, the bailles below the rotor being exposed to atmosphere on the outer peripheries only. and an enclosing casing spaced from the upper section of cooling tower, in combination, a I

chimney below the last mentioned means andradially from the last mentioned means through said curtain, a closure for the bottom of the chimney, the baffles below the last mentioned means being open to the atmosphere on their outer peripheries, and an enclosing casing spaced from the peripheries of the baffies surrounding and above the last mentioned means,

5. In a cooling apparatus for liquids, in combination, a tower including means for forming liquid into an annular curtain, means to periodically interrupt and reform the curtain to retard the fall of the liquid, an air circulating device within said curtain intermediate the ends thereof, means to limit its suction to one axial direction whereby air is drawn radially in through that portion of the curtain on the suction side of said device, and means to deliver air radially outwardly from said device through the portion of the curtain surrounding it.

6. In a cooling apparatus for liquids, in combination, a tower including means for forming liq-v uid into an annular curtain, means to periodically interrupt and reform the curtain to retard the fall of the liquid, an air circulating device within said curtain intermediate the ends thereof, means to limit its suction to one axial direction whereby air is drawn radially in through that portion of the curtain on the suction side of said device, means to deliver air radially outwardly from said device through the portion of the curtain surrounding it, a closed shell surrounding the second mentioned portion of the curtain and an adjacent portion and spaced therefrom so as to reverse the air flowing out through the second portion and direct it radially inwardly through the third portion of the curtain whereby the air is exhausted axially from the interior of the curtain.

7. In a liquid cooling tower, in combination, a superimposed series of bodies forming a chimneylike structure, means above said series to distribute hot liquid uniformly over the topmost baiile,

means below the lowest baflie to catch the cooled liquid, an air circulating device within said bailie series between top and bottom thereof, the battles below said device being exposed to atmosphere on their outer peripheries, an enclosing'casing surrounding the baiiles at and above said device, and

a spray eliminator above the center of the baiile stack, said device being constructed to draw air in through the baflles below said deviceand discharge it through the other bodies.

8. In a liquid cooling tower, in combination, a superimposed series of baiiles forming a chimney-like structure, means above said series to distribute hot liquid uniformly over the topmost battle, means below the lowest bafile to catch the partly cooled'liquid and redistribute it, a second similar series of baflles therebelow, an air circulating device within said first mentioned series with its intake on the level with the partially cooled liquid distributor, means closingthe bot-- tom of the tower, means closing the top of said device and opening in the center of the baiiles, the baffies below said device being exposed to atmosphere on their outer peripheries only and assume homes and extending between the liquid distrlbue an enclosing casing spaced from the upper section of bames and extending between the liquid distributors, said device being constructed to draw air in through the lower battles and dis charge it through the other baflles.

9. A cooling tower for liquids including in combination, a vertical series of superimposed horizontal bailies forming a chimney-like structure open at the top, means 'at the top of said series for supplying hot liquid on to the top baflie, a receptacle at the ,bottom of the series to collect the cooled liquid, *9. second means intermediate the height of said series of baiiles to collect liq uid falling from the baflle next above the same and distribute it onto the baiiie immediately under said second means, air circulating'means disposed within said baiiles intermediate their height adapted to draw air inwardly between the baiiies below said second means, and discharge it outwardly through the lower portion of baflies next above said second means, and a casing around and spaced from the series of bailies above said second meansforming an outer air space closed at the top thereof and serving to redirect the air inwardly through the upper portion of baffles into the center space of the tower, from where it passes out through the open top of the tower.

10. In a liquid cooling tower, means for forming liquid into a periodically interrupted curtain, a horizontal 'sectionof which forms a substantially closed figure, means disposed within said curtain to create a currentof air transversely inwardly of said curtain below the current ore-- ating means and radially therefrom through said curtain and an'enclosing casing spaced from said curtain surrounding and above said current creating means. a

ii. In a liquid cooling tower, in combination,

substantially superposed banks of units each ineluding substantially superposed baffles arranged to form a chimney-like structure, means to distribute liquid over the top baflie of each unit whereby the liquid drips downwardly from baiiie to baiiie, and means within the chimney to draw air transversely inwardly through a bank of units below said means, and then transversely outwardly through a bank of units at a higher elevation.

12. In a liquid cooling tower, in combination, substantially superposed banks of units each including substantially superposed baifles all arranged to form a hollow'tower, means to distribute liquid over the top baille of each unit whereby the liquid drips downwardly from baffie to baflie, means below the lowest unit to collect the cooled liquid, a squirrel cage type fan rotor within said tower intermediate its height to draw air transversely inwardly through the lowest bank of units and discharge it transversely outwardly through a higher bank of units, and a casing surrounding the units at and above the rotor.

13. Cooling apparatus for liquids including in combination, spaced substantially superposed liquid baflies arranged to form a hollow tower, an air circulating device within said tower intermediate its height having its suction limited to one axal direction whereby air is drawn transversely inwardly through that portion of the jacent portion and spaced therefrom so as to reverse the air flowing out through the second portion and direct it transversely inwardly through the third portion of the tower.

14. Cooling apparatus for liquids, including in combination, vertically spaced liquid bafiles arranged to form a hollow tower, an air circulating device within said tower intermediate the ends thereof, means to limit its suction to one axial direction whereby air is drawn transversely in through the portion of the tower on the suction side of said device, and means to deliver air transversely outwardly through the portion of the tower surrounding said device.

15. In cooling apparatus for liquids, including in combination, vertically spaced liquid baflles arranged to form a hollow tower, a single air circulating device disposed within the tower intermediate its ends, and air deflecting means acting with the said device to cause the same air to pass through the tower wall a plurality of times and in alternate directions.

16. In a liquid cooling tower, in combination,

means for forming liquid into a periodically interrupted curtain, a horizontal section of which forms a substantially closed figure, means disposed within said curtain to create a current of air axially of said curtain below the current creating means and radially therefrom through said curtain, the periphery of said curtain being exposed to air below the current creating means and an enclosing casing spaced from said curtain and surrounding and above said current creating means.

17. In a liquid cooling tower, in combination, means for forming the liquid into a periodically interrupted vertical curtain a horizontal section of which is in the form of a substantially closed figure, air circulating means disposed within said curtain to draw air through all parts of the lower portion of said curtain which is exposed to air and discharge it through all parts of the next higher portion, and means to guide said discharged air back through another portion of the curtain.

STEWART C. COEY. 

